The population of the region is almost entirely Tibetan, with Han (Chinese), Hui (Chinese Muslims), Hu, Monba, and other minority nationalities. Thus, the majority of the people of Tibet have the same ethnic origin, have traditionally practiced the same religion, and speak the same language.

Tibetan, member of either of two physical types of people who inhabit Tibet or nearby regions and speak Tibetan. Tibetans are sometimes distinguished by physical type, notably (1) a round-headed group found mostly in the cultivated river valleys of central and western Tibet, who resemble the Chinese and Myanmar (Burmese), and (2) a long-headed group who tend to be tall and angular in build, with aquiline noses, found among the noble families in central Tibet and generally among the nomads of the east and northeast.

The number of Tibetans in Tibet proper (and other areas in western China) is estimated at around 4.2 million, with perhaps an additional 2 million in the Tibetan ethnic areas of Bhutan, India, northern Nepal, and the Ladakh region of Jammu and Kashmir.

Prior to the Chinese annexation of Tibet in 1959, social classes among the Tibetans could be defined in terms of opposition: cleric versus lay, noble versus peasant, merchant versus labourer, agriculturalist versus nomad, and trader versus townsman. The agriculturalists traditionally formed the peasantry of Tibet, most of them working as tenants or hired labourers on land owned by the monasteries or the nobility. The herdsmen and shepherds pastured their flocks on the high steppes; some of them remained in the lowlands during the winter and migrated upward in summer. Before 1959 it was estimated that about one-quarter of the population belonged to the clerical order. The monasteries were the main seats of learning. Tibetan Buddhism is an admixture of Buddhist teachings and the pre-Buddhist religion, Bon.